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###### Department of Health and Human Services

###### Food and Drug Administration

          - 21 CFR Parts 510 and 522

# AGENCY:

Food and Drug Administration, HHS.

# ACTION:

Final rule.

# SUMMARY:

                        The Food and Drug Administration (FDA) is amending the animal drug regulations that reflect approval of two new animal drug applications (NADAs) for a suspension implant of estradiol benzoate microspheres used in steers and heifers fed in confinement for slaughter for increased rate of weight gain and improved feed efficiency, and in suckling beef calves for increased rate of weight gain. In a notice published elsewhere in this issue of the                         **Federal Register**                        , FDA has withdrawn approval of the NADAs.                    

# DATES:

This rule is effective April 19, 2007.

# FOR FURTHER INFORMATION CONTACT:

                         Pamela K. Esposito, Center for Veterinary Medicine (HFV-212), Food and Drug Administration, 7519 Standish Pl., Rockville, MD 20855, 240-276-9067; e-mail:                         *pamela.esposito@fda.hhs.gov*.                    

# SUPPLEMENTARY INFORMATION:

PR Pharmaceuticals, Inc., 1716 Heath Pkwy., Fort Collins, CO 80524, has requested that FDA withdraw approval of NADA 141-040 for DURALEASE (estradiol benzoate), a suspension implant of estradiol benzoate microspheres used in steers and heifers fed in confinement for slaughter for increased rate of weight gain and improved feed efficiency and NADA 141-041 for CELERIN-C (estradiol benzoate), a similar product used in suckling beef calves for increased rate of weight gain. This action is requested because the products are no longer manufactured or marketed.

                    In a notice published elsewhere in this issue of the                     **Federal Register**                    , FDA gave notice that approval of NADA 141-040 and NADA 141-041 and all supplements and amendments thereto, were withdrawn, as of September 29, 2006.                

Following the withdrawal of approval of these NADAs, PR Pharmaceuticals, Inc., is no longer a sponsor of an approved application. Therefore, 21 CFR 510.600(c) is amended to remove entries for this firm. As provided in the regulatory text of this document, the animal drug regulations are amended to reflect the withdrawal of approval.

This rule does not meet the definition of “rule” in 5 U.S.C. 804(3)(A) because it is a rule of “particular applicability.” Therefore, it is not subject to the congressional review requirements in 5 U.S.C. 801-808.

# List of Subjects

### 21 CFR Part 510

      - Administrative practice and procedure
      - Animal drugs
      - Labeling
      - Reporting and recordkeeping requirements

### 21 CFR Part 522

      - Animal drugs

Therefore, under the Federal Food, Drug and Cosmetic Act and under authority delegated to the Commissioner of Food and Drugs and redelegated to the Center for Veterinary Medicine, 21 CFR parts 510 and 522 are amended as follows:

# PART 510—NEW ANIMAL DRUGS 

1. The authority citation for 21 CFR part 510 continues to read as follows:

Authority:21 U.S.C. 321, 331, 351, 352, 353, 360b, 371, 379e.

§ 510.600 

2. In § 510.600, in the table in paragraph (c)(1), remove the entry for “PR Pharmaceuticals, Inc.”; and in the table in paragraph (c)(2) remove the entry for “067210”. 

# PART 522—IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS

3. The authority citation for 21 CFR part 522 continues to read as follows:

Authority:21 U.S.C. 360b.

§ 522.841 

4. Remove § 522.841. 

Dated: April 9, 2007.

Bernadette Dunham,

Deputy Director, Center for Veterinary Medicine.

[FR Doc. E7-7458 Filed 4-18-07; 8:45 am]

BILLING CODE 4160-01-S